JPH03190254A - Method of measuring resistance of conductor in circuit board - Google Patents

Abstract

PURPOSE:To eliminate the restriction on the matrix pitch of electrodes on a circuit board and hence improve the accuracy of measurement by setting the size of a contactor in conformity with the number of electrodes on said circuit board. CONSTITUTION:A plurality of fader-like contactors 22 are fixed with probe cards 20 and 20' so that they may be kept off from each other on one sided surface of the peripheral part around a hole on an insulation board 21 equipped with a hole 20 larger than a circuit board 1 at least. The contactors 22 are laid out reversely in a radial manner inward from the peripheral part so that their tips may correspond with the specified positions of the electrodes on the circuit board 1. Furthermore, the inner side tip of the contactors 22 are bent substantially at a right angle into a rising direction from the insulated board 21. This construction makes it possible to measure the conductivity resistance of the electrodes including the circuit board 1 where the electrodes are formed near the peripheral part accurately and efficiently as well.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for measuring conductor resistance between the front and back electrodes of a circuit board in which electrodes that conduct between the front and back surfaces are formed with high density, it is possible to accurately (and efficiently measure) the conductor resistance. A method for measuring conductor resistance between the front and back electrodes of a circuit board, which is provided with electrodes that are electrically connected to the front and back surfaces at positions corresponding to a plurality of electrodes of a semiconductor element, with the aim of improving productivity in the circuit board. A circuit board holder holding and fixing the circuit board with its opposing parallel peripheral surfaces is provided with holes larger than the circuit board at corresponding positions on both sides sandwiching the circuit board in the thickness direction,
A plurality of feder-like contacts are arranged on one side of the hole periphery in a reverse radial direction inward from the hole periphery, the tips of which are positioned in correspondence with respective electrode positions on the circuit board, and a distance from the circuit board. After arranging two equal probe cards having at least prediction means with their federated contact mounting surfaces facing each other, each federated contact of one probe card is connected to one side force ( At the same time, each feder-shaped contact of the other probe card is connected to the other sense point of the resistance measuring device, and the two probe cards are synchronously brought close to each other to first perform the above prediction. After confirming the distance between the feder-like contact and the circuit board by means of the means, the two probe cards are further brought close to each other so that each tip of the feder-like contact is brought into contact with the corresponding electrode of the circuit board at the same time. Configure.

[Industrial application field]

The present invention relates to a method for measuring conductor resistance between front and back electrodes of a circuit board in which electrodes that conduct between the front and back surfaces are formed with high density, and in particular, it is possible to improve productivity by accurately and efficiently measuring conductor resistance. The present invention relates to a method for measuring conductor resistance of a circuit board.

Today, with the increasing integration of circuit configurations, in addition to increasing the density of circuit board patterns, in order to make the most effective use of the pattern formation area of the circuit board, it is necessary to use the area near the periphery of the circuit board or use both sides of the board. However, particularly when both sides of the substrate are used, how to accurately measure the conductor resistance between the front and back electrodes is a major problem.

[Conventional technology]

FIG. 2 is a diagram illustrating a conventional method for measuring conductor resistance of a circuit board, in which (a) shows an example of a circuit board to be measured, and (b)
) is an enlarged sectional view illustrating the state at the time of measurement.

In Figure (a), a circuit board 1 includes electrodes 1c having a diameter d of about 350 μm and electrodes 1c having a pitch p of about 900 μm, conductive through through holes ib, on both the front and back surfaces of a multilayer ceramic substrate 1a having a thickness of about 1 mm. They are arranged in a matrix.

2 is a diagram (b) showing the case of measuring the conductor resistance between the corresponding electrodes 1c, lc' of the circuit board 1, and 2 is the diagram (a).
This is a circuit board holder equipped with a through hole 2a into which the circuit board 1 shown in FIG.

In particular, guide walls are provided on both sides of the circuit board holder 2 on the outside of the periphery of the through hole 2a so that two equal probe cards 3 can be moved individually in the thickness direction of the holder 2 while facing each other. 2b and 2b' are formed in a concave state.

In the figure, for ease of understanding, the probe card located at the top of the circuit board I is designated as 3, and the probe card located at the bottom is designated as 3'.

Further, the probe cards 3 and 3' are provided with protrusions 3a on their peripheries that fit into the guide walls 2b and 2b' of the circuit board holder 2, and the circuit board l is provided inside the protrusions 3a.
Contact probe pins (hereinafter simply referred to as probe pins) are located at positions corresponding to the plurality of electrodes 1c and lc'.
4 is fixed such that each movable pin 4a faces the protrusion 3a side.

Note that a coil spring 4b is provided inside each probe pin 4 so as to press the movable pin 4a in one direction.

Therefore, the circuit board (2) is inserted into the through-hole 2a of the circuit board holder 2 with its outer shape aligned, and the probe card 3 is inserted into the guide walls 2b and 2b' of the holder 2, respectively. When these are fitted together, the movable pins 4a of the probe pins 4 are opposed to the electrodes 1c and lc' on the front and back surfaces of the circuit board l, respectively.

At this point, when a mechanism (not shown) is operated to move the probe cards 3 and 3' in the directions shown by the arrows al and a2, the opposing probe pins 4 are connected to the conductive electrodes 1c and lc' of the circuit board 1. It can be connected via.

Therefore, for example, each probe pin 4 on the probe card 3 side is connected to one side force of the resistance measuring device 6 using the wiring material 5.
) point, and also connect each probe pin 4 on the probe card 3' side to the other sense (
Sense) point, and the personal computer 7 connected to the resistance measuring device 6 measures the correspondence between the opposing probe pins 4, and simultaneously measures the conductor resistance between each electrode 1c and lc' of the circuit board 1. can do.

Particularly in this case, each movable pin 4a is connected to each electrode 1c.

The coil spring 4 installed inside the IC' at the same time as it comes into contact with
b ensures a predetermined initial contact force.

Therefore, each movable pin 4a corresponds to the corresponding electrode 1c of the circuit board l.
, lc', the circuit board l is positioned in a balanced manner so that the sum of the contact forces received from both sides of the circuit board l is equal, so that it swings in the thickness direction within the through hole 2a of the circuit board holder 2. As a result, the contact force between each movable pin 4a and the electrodes 1c, lc' becomes almost equal, so the conductor resistance between the electrodes 1c, lc' can be measured in a stable state at all times. .

However, in the case of such a conductor resistance measurement method, there is a restriction on the matrix pitch (p) of the electrodes 1c, lc' formed on the circuit board 1 due to (1) the outer diameter d+ of the probe pin 4;

For example, the outer diameter d1 of the probe pin 4 is currently about 900 μm at the minimum, but in recent years the outer diameter d1 of the probe pin 4 is approximately 900 μm.
The matrix pitch (p) of c' is less than 900 μm (
For example, about 450 μm) may be required.

Therefore, in such a case, it is not possible to measure the conductor resistance of all the electrodes at once, so the measurement must be carried out in parts while shifting them little by little, and as a result, the measurement requires many man-hours.

■It is difficult to arrange multiple probe pins 4 on each probe card 3.3' under the same conditions, and some deviations occur in the axial and lateral directions, and the probe pins 4 have an initial contact force due to the coil spring 4b. Therefore, it is difficult to make the contact force against the circuit board l uniform over the entire surface.

Further, the circuit board l swings somewhat relative to the through hole 2a of the circuit board holder 2.

Therefore, the measured value of the conductor resistance may contain an error because the contact force of the movable pin with respect to the electrode varies depending on the position or lateral deviation occurs between the electrode position of the circuit board 1 and the movable pin.

Therefore, in order to obtain a particularly accurate conductor resistance value, the circuit board l
Each of the electrodes 1c and lc' must be measured one by one using the opposing probe pins 4, which requires a large number of man-hours.

■In order to effectively utilize the electrode formation area, in the case of a circuit board where electrodes are formed close to the periphery, the probe pin 4 cannot be placed close to the periphery, so measure the conductor resistance of the electrode in the area. Can not do it.

Therefore, in order to cope with this, it is necessary to hold and fix the circuit board l on the circumferential surface of the circuit board 1, but in this case, since the swinging of the circuit board 1 in the thickness direction is restricted, the conductor resistance An error may occur in the measured value or the circuit board 1 may be destroyed.

There are drawbacks such as.

[Problem to be solved by the invention]

The conventional method for measuring conductor resistance of circuit boards has the problem that there are restrictions on the matrix pitch of electrodes formed on the circuit board, and that it takes a lot of measurement time to improve the measurement accuracy of conductor resistance values. It is not possible to measure the conductor resistance of the electrodes located near the periphery of a circuit board on which electrodes are formed. There was a problem.

[Means to solve the problem]

The above problem is a method for measuring conductor resistance between the front and back electrodes of a circuit board that is provided with electrodes that are conductive to the front and back surfaces at positions corresponding to a plurality of electrodes of a semiconductor element. A circuit board holder holding and fixing the circuit board between the surfaces thereof is provided with holes larger than the circuit board at corresponding positions on both sides sandwiching the circuit board in the thickness direction, and one side of the periphery of the hole has a hole extending inward from the periphery of the hole. a plurality of feder-like contacts arranged in a radial manner, the tips of which are positioned in correspondence with respective electrode positions on the circuit board;
After arranging two equal probe cards equipped with at least means for predicting the spacing with respect to the circuit board with their federated contact mounting surfaces facing each other, the resistance of each federated contact on one probe card is measured. Force on one side of the vessel (Fou
rce) and connect each feder-like contact of the other probe card to the other sense (5en) of the resistance measuring instrument.
ce) and bring the two probe cards synchronously close together to first check the distance between the fader-shaped contact and the circuit board using the above-mentioned prediction means, and then connect the two probe cards to the circuit board. This problem is solved by a method of measuring the conductor resistance of a circuit board in which each tip of a feder-like contact is brought into close contact with a corresponding electrode of the circuit board at the same time.

[For production]

If a probe card is configured so that a contact with an initial contact force of zero is brought into contact with the front and back electrodes of a circuit board at the same time, and then the contacts are simultaneously bent to obtain a predetermined contact force, the circuit board will always be exposed from both sides. Since the same pressing force is applied, the position in the thickness direction does not change.

In the present invention, the circuit board is held and fixed on its peripheral surface, and
A plurality of feder-like contacts are arranged around the hole of an insulating board having a hole larger than the circuit board in a reverse radial direction inward from the peripheral part so that the tips thereof correspond to the positions of the respective electrodes on the circuit board. With my child.

Two equal probe cards each having means for predicting a distance with respect to the circuit board are disposed to face each other with the circuit board interposed therebetween.

In this case, when the two probe cards are brought close to each other, the distance between the two probe cards and the circuit board can be predicted by the prediction means, so it is easy to bring the tips of the feder-shaped contacts into contact with each electrode of the circuit board on the front and back sides at the same time. Since the initial contact force of the federated contact is set to zero, the circuit board does not move in the thickness direction.

Furthermore, even if the probe card is brought closer, the circuit board always receives equal pressing force from both sides, so it will not move in the thickness direction.

Therefore, by setting the size of the federated contact according to the number of electrodes on the circuit board, it is possible to remove the restriction on the matrix pitch of the electrodes on the circuit board, improve measurement accuracy, and make it possible to extend the electrodes to the vicinity of the periphery. It can also be applied to a circuit board that has been formed.

〔Example〕

FIG. 1 is a diagram illustrating a method for measuring conductor resistance of a circuit board according to the present invention, and (A) is a diagram showing an example of the configuration of a measuring jig;
(B), (C), and (D) are cross-sectional views illustrating the measurement situation using the jig.

Note that (B), (C), and (D) are cross-sectional views of the probe card and, in turn, the circuit board in Figure (A), taken approximately along the center line C and viewed from the direction of the arrow. (C) shows the state immediately before measurement, and (D) shows the state at the time of measurement.

In Figure (A), 1 is the circuit board explained in Figure 2,
In the following figures, descriptions of the electrodes 1c and lc' shown in FIG. 2 are omitted to avoid complication of the drawings.

Further, IO indicates a circuit board holder that holds and fixes the circuit board 1 by sandwiching it between two opposing circumferential surfaces, and in particular, the circuit board holder 10 includes a base 11 having a dovetail,
Two restraining metal fittings 12 and 12' having dovetail grooves 12a that fit into the dovetail Ila in the width direction near the longitudinal ends, and two holding metal fittings 12 attached to the base 11.
．． 12', and a coil spring 13 that constantly attracts the metal 12'.Furthermore, at the other end of the holding metal fitting 12°12', the opposing parallel circumferential surface of the circuit board l is connected to the dovetail groove 12a.
A pressing surface 12b for holding the press 1 is formed in a direction parallel to the pressing surface 12b.

Note that 14 in the figure is a stay on which both ends of the coil spring 13 are hung.

Therefore, I attached the metal fitting 12.12 to the dovetail Ila of the base II.
After fitting each of the dovetail grooves 12a of No. 1 so that the pressing surfaces 12b face each other, when both ends of the coil spring 13 are hung on the stay 14, the two restraining metal fittings 12 and 12' are moved as indicated by the arrows shown in the figure, b2. Move in the direction of approaching.

Therefore, the circuit board l can be held between the opposing pressing surfaces 12b as shown in the figure.

On the other hand, the "mouth" shaped probe cards 20 and 20' located vertically across the circuit board holder 10 are the same, but in the figure, for convenience, the probe card located at the top is designated as 20, and the bottom The probe card located at is designated as 20'.

In particular, the probe card 20.20' includes an insulating board 21 having a hole 20a larger than the circuit board l.
A plurality of fader-like contacts (hereinafter referred to as (simply referred to as contacts) 22 are fixed so as not to come into contact with each other, and furthermore, the inner tips of the contacts 22 are bent at a substantially right angle in the direction rising from the insulating substrate.

Further, in an area of the insulating substrate 21 excluding the area where the contact 22 is present on the side where the contact 22 is fixed, the circuit board holder 10
A plurality of (two in the figure) push button switches 23 connected to a detector 23a are installed in the area where the holding fitting 12 is present, and guide pins are installed at predetermined positions in the area other than the area where the holding fitting 12 is present. 24 and a guide hole 25 having a diameter that fits the guide pin 24 are provided, respectively.

Therefore, the probe card 2 is
0.20' are arranged so that the fixed surfaces of the contacts 22 face each other, and the guide pins 24 of each probe card 20.20' are fitted into the guide holes 25 of the probe cards 20', 20, for example (not shown). When the two probe cards are brought close to each other synchronously by a moving mechanism or the like, the push button switches 23 of each probe card first come into contact with the surface of the holding fitting 12 of the circuit board holder 10, and the electric signals of the push button switches 23 are detected by the detector 23a. Probe card 20.2 by detecting with
It is possible to predict the distance between 0' and the holding fitting 12, as well as the tip of the contactor 22 and the circuit board 1.

Figure (B) shows the state at this point.

Therefore, if, for example, the circuit board holder IO is slightly moved in the vertical direction by a mechanism (not shown) so that the electric signals can be detected almost simultaneously, then the probe cards 20 and 20' are brought closer together by the moving mechanism, etc. probe card 20
．． The tip of each contactor 22 of 20' can be brought into contact with the corresponding front and back electrode surfaces of the circuit board 1 at the same time.

Figure (C) shows this state.

Particularly in this case, since the initial contact force of each contactor 22 becomes zero, the circuit board 1 does not move in its thickness direction.

Furthermore, even if the probe cards 20, 20' are brought closer to each other to increase the contact force against the front and back electrode surfaces of each contactor 22, the circuit board 1 will be pressed with the same pressure from both sides. The circuit board l will not be destroyed or fall off from the holding fittings 12° 12' of the circuit board holder lO.

Figure (D) shows the state at this point.

Therefore, similarly to FIG. 2, for example, each contact 22 of the probe card 20 is connected to one side force (
4) point and also connect the probe card 20'
Connect each contact 22 on the side to another sense point of the resistance measuring device 6 using the wiring material 5', and further check the correspondence between the opposing contacts 22 using a computer 7 connected to the resistance measuring device 6. By doing so, the conductor resistance between each electrode of the circuit board 1 can be measured simultaneously in a stable state.

Particularly in this case, since the circuit board 1 is held and fixed on its peripheral surface, the present invention can also be applied to a circuit board in which electrodes are formed on the entire surface including the vicinity of the periphery.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a method for measuring the conductor resistance of a circuit board, which can accurately and efficiently measure the conductor resistance of an electrode, including a circuit board on which electrodes are formed up to the vicinity of the periphery.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a method for measuring the conductor resistance of a circuit board according to the present invention, and FIG. 2 is a diagram illustrating a conventional method for measuring the conductor resistance of a circuit board. In the figure, l is the circuit board, 5.5' is the wiring material, 6 is the resistance measuring device, 7 is the computer, 10 is the circuit board holder, 11 is the base, lla is the dovetail, 12.12'
1 is a retaining metal fitting, 12a is a dovetail groove, 13 is a coil spring,
14 is a stay, 20.20' is a probe card, 20a is a hole, 21 is an insulating board, 22 is a fader-like contact, 23 is a push button switch, 23a is a detector, 24 is a guide pin, and 25 is a guide hole. represent

Claims (1)

[Claims] A method for measuring conductor resistance between the front and back electrodes of a circuit board, which is provided with electrodes that are electrically connected to the front and back surfaces at positions corresponding to a plurality of electrodes of a semiconductor element, the method comprising: placing the circuit board (1) on its opposite side; Holes (20a) larger than the circuit board (1) are provided at corresponding positions on both sides of the circuit board (1) sandwiching the circuit board (1) in the thickness direction of the circuit board holder (10) which is held and fixed by the parallel circumferential surfaces of the circuit board holder (10). A plurality of feder-like contacts (22) located on one side of the hole periphery in a reverse radial direction inward from the hole periphery, the tips of which are positioned in correspondence with each electrode position of the circuit board (1); two equal probe cards (20, 20') comprising at least means for predicting the spacing relative to the circuit board (1);
After arranging the federated contact mounting surfaces facing each other, each federated contact (2) of one probe card (20) is placed.
2) on one side of the resistance measuring device (6).
) point and the other probe card (20')
Connect each feder-like contact (22) of the above to the other sense point of the resistance measuring device (6), and bring the two probe cards (20, 20') synchronously close to each other. The feeder-like contact (22) and the circuit board (1) are detected by the predictive means.
After confirming the distance between
2) A method for measuring conductor resistance of a circuit board, characterized in that each tip of (2) is brought into contact with a corresponding electrode of the circuit board (1) at the same time.